Hengli Petrochemical — C9 Separation (2021) — Brine Chiller Package for Aromatic Hydrocarbon Processing
By Qiangbin Chu · Sales Manager & Operations Lead
Hengli Petrochemical's Changxing Island complex in Dalian is a fully integrated refining and petrochemical facility. The C9 separation unit processes heavy aromatic hydrocarbon fractions from the naphtha cracker, separating C9+ aromatics into individual product streams including indene, coumarone, mesitylene, and heavy aromatic solvents used in coatings, adhesives, and chemical synthesis.
| Client | Hengli Petrochemical (Changxing Island, Dalian) |
| Plant / Unit | C9 Separation — Aromatic Hydrocarbon Fractionation |
| Equipment | Brine Chiller Package × 2 |
| Design Code | GB |
| Cooling Capacity | 460 kW per unit |
| Motor Power | 250 kW |
| Refrigerant | Propylene (R1270) |
| Coolant | Ethylene glycol |
| Design Institute | Nanjing Jinling |
| Year | 2021 |
Customer Background
Hengli Petrochemical’s Changxing Island complex in Dalian is a fully integrated refining and petrochemical facility. The C9 separation unit processes heavy aromatic hydrocarbon fractions from the naphtha cracker, separating C9+ aromatics into individual product streams including indene, coumarone, mesitylene, and heavy aromatic solvents used in coatings, adhesives, and chemical synthesis.
C9 fractionation requires precise temperature control at multiple column stages. Sub-ambient cooling with ethylene glycol brine is used to condense specific fractions and control column reflux temperatures. The brine chiller packages provide the low-temperature cooling loop that circulates chilled ethylene glycol to the process heat exchangers.
The C9 separation unit was added as part of the complex’s downstream expansion, extracting additional value from the naphtha cracker’s heavy fraction output. Nanjing Jinling, a design institute with deep experience in aromatic hydrocarbon processing, specified the refrigeration equipment requirements based on the fractionation column’s thermal duty profile.
Challenges and Engineering Requirements
Process Temperature Control in petrochemical processing
Hengli Petrochemical required precise low-temperature cooling for Brine Chiller Package × 2 service in the petrochemical processing sector. The brine chiller system must maintain stable outlet temperatures within narrow tolerances despite variable process heat loads. Fluctuations in feed composition, ambient temperature swings, and seasonal load variations all affect the refrigeration duty — the system must respond to these changes while protecting compressor operation from surge and liquid carryover.
Refrigerant Selection and Safety
The choice of Propylene (R1270) reflects the balance between thermodynamic efficiency at the target evaporating temperature, compatibility with the plant’s existing refrigerant infrastructure, and safety classification under the applicable code. Each refrigerant brings specific considerations: flammability limits for hydrocarbon refrigerants, operating pressure ranges that affect component sizing, and oil miscibility that influences compressor lubrication system design.
Integration with EPC Engineering
The chiller packages were specified and documented by Nanjing Jinling as part of a larger process unit. This means every interface — brine supply/return connections, electrical load requirements, control signal protocols, and physical footprint — must match the EPC’s plot plan and P&ID exactly. Any deviation requires formal design change management, adding time and cost to the project.
Why Hengli Petrochemical Selected Lmart
Integrated refrigeration package capability. Lmart designs and manufactures complete refrigeration systems — compressor selection, heat exchanger sizing, piping layout, control logic, and skid-frame engineering — as a single-source supplier. This eliminates the interface risks that arise when the chiller vendor, vessel fabricator, and system integrator are separate companies.
Process refrigerant experience. Lmart has delivered refrigeration packages using propylene, propane, ammonia, R134a, and other process refrigerants across petrochemical, chemical, and marine applications. This experience base means the engineering team understands the specific requirements of each refrigerant — safety classifications, oil management, capacity control methods — without a learning curve.
Repeat performance. Lmart has delivered equipment to Hengli Petrochemical and similar clients in the petrochemical processing sector, demonstrating consistent quality and on-time delivery performance across multiple projects.
Technical Scope and Specifications
Two identical brine chiller packages, each rated at 460 kW cooling capacity, provide redundant cooling for the C9 separation process. The propylene (R1270) refrigerant circuit uses screw compressors driven by 250 kW motors. Ethylene glycol brine is chilled and circulated to the process-side heat exchangers in the fractionation train.
Key design features:
- Redundant configuration: Two identical units allow continued operation during maintenance of either chiller, ensuring uninterrupted C9 fractionation
- Propylene refrigerant (R1270): Selected for its thermodynamic efficiency at the target evaporating temperature range and compatibility with the petrochemical plant’s existing refrigerant infrastructure
- Ethylene glycol brine circuit: Provides freeze protection and corrosion inhibition in the secondary cooling loop, with glycol concentration selected for the required minimum operating temperature
- Nanjing Jinling engineering: Equipment designed and documented to Nanjing Jinling’s specifications for integration into the existing C9 separation unit
This project represents the third Hengli Petrochemical order fulfilled by Lmart, following the HDPE brine chillers and ethylene tank farm direct cooling system delivered in 2018. The repeat order reflects proven reliability and quality consistency across Lmart’s refrigeration product line.
Delivery and Quality Assurance
Both chiller packages were factory-assembled, pressure-tested, and electrically verified at Lmart’s Zhangjiagang facility before shipment to the Changxing Island complex. The packages were designed and documented to Nanjing Jinling’s engineering specifications, including material certificates, weld inspection reports, and performance test records.
The C9 separation brine chillers demonstrate Lmart’s sustained relationship with Hengli Petrochemical across multiple project phases and plant units. From the initial HDPE and ethylene tank farm orders in 2018 to the C9 separation unit in 2021, the consistent selection of Lmart as the refrigeration equipment supplier reflects confidence in product quality and after-sales support.
Results and Business Impact
Lmart successfully delivered 2 units of Brine Chiller Package × 2 to Hengli Petrochemical, meeting the project’s quality, schedule, and documentation requirements. The equipment was manufactured to GB standards, with full documentation packages accepted by the client and applicable inspection authorities.
This project reinforces Lmart’s position as a qualified manufacturer for petrochemical processing applications, demonstrating the company’s ability to deliver equipment that meets international quality and certification standards.
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Customer Voice
“The equipment was delivered on schedule and the documentation package was complete. The quality of fabrication met our inspection requirements.”
— Hengli Petrochemical project team (paraphrased from project review)
Note: Lmart respects client confidentiality. Specific contact references are available upon request during the qualification process.